Silicon carbide thyristors are described, for example, in U.S. Pat. No. 5,539,217 (the '217 patent) the disclosure of which is incorporated herein by reference as if set forth fully. The thyristors described in the '217 patent are three terminal devices having a gate and one of an anode or a cathode on a first side of the device and the other of the anode and the cathode on the opposite side of the device. Such silicon carbide thyristors may exhibit improved power handling capabilities over similar silicon thyristors.
Light-activated thyristors having an integrated light source and a silicon carbide active layer have been described in U.S. Pat. No. 5,663,580. Such devices may include four terminal devices and include anode and cathode terminals for a light emitting diode which acts to trigger a thyristor having its own anode and cathode terminals.
Silicon thyristors which are light activated have been utilized in high power applications. For example, optically triggered parallel lateral thyristors are described in U.S. Pat. No. 4,779,126.
While silicon carbide thyristors may provide improved power handling capabilities over comparably sized silicon devices, it may be difficult to create large scale thyristors in silicon carbide. For example, in silicon a single thyristor may be made on a wafer such that the thyristor is substantially the same size as the wafer. However, manufacturing defect free silicon carbide wafers may be difficult, if not impossible. Thus, a device which consumes an entire wafer may have defects incorporated into the device which may limit its performance.